1. Field of the Invention
The present invention relates to a non membrane-based gas pressure microsensor. It is based on the microbridge flow sensor and since it is not membrane-based it is not subject to breakage caused by overpressure. It describes a method to determine gas pressure from basically thermal conductivity, k, and specific heat, c.sub.pv.
2. Background
Prior art gas pressure microsensors are typically based on sensing the deflection of a membrane either piezoresistively or capacitatively, with inherent limitations imposed by allowable maximum pressure to avoid membrane breakage and by acceptable sensitivity at the low pressure end. Over-pressure protection is needed and costly. A non membrane-based absolute pressure microsensor is based on sensing thermal conductivity, but has a limited high pressure range and has a somewhat gas composition dependent output.